1. Field of the Invention
The present invention relates to a bubbly water outlet device attached to an end of a spout of a faucet, shower head or the like for making bubbles in the water flow.
2. Description of the Prior Art
There have been such faucets which are provided with bubbly water outlet for reducing flowing noises and splashing noises in sinks or the like and/or to reduce splashes. One of popular outlets is disclosed in Japanese Patent Publication (KOKOKU) No. 63-31621.
FIG. 66 is a sectional view schematically illustrating a bubbly water outlet which is disclosed in the above publication and is also of a conventional type. In the Figure, an outlet cap 901 is fixed to an end of a spout 900 of a faucet, and accommodates a pressure reducing plate 902 provided with many small holes 902a. At a downstream side to the pressure reducing plate 902, a peripheral wall of the outlet cap 901 is provided with air holes 903 for introducing external air into supplied water, and a plurality of baffle nets 904 for straightening a water flow is also provided at an outlet end.
In this bubbly water outlet, the water from the spout 900 is accelerated as it passes through the small holes 902a in the pressure reducing plate 902. Thereby, a pressure at a portion downstream of the pressure reducing plate 902 and inside the outlet cap 901 is reduced, so that the external air is sucked therein through the air holes 903, and thus the air is mixed with the water, resulting in bubbling of the water. Since the baffle net 904 has fine meshes, the water is intensely stirred as it collides with the baffle net 904 and flows through it, which also promotes the bubbling.
However, since the water from the spout 900 flows through the holes 902a in the pressure reducing plate 900, pressure loss is caused in the flow. It is therefore necessary to open the faucet equal to or wider than an appropriate degree for obtaining an appropriate discharge pressure, otherwise comfortable use and sufficient bubbling can not be achieved.
Since two members, i.e., the pressure reducing plate 902 and the baffle net 904 are arranged, debris in the water may close them and/or scale may stick to them. Therefore, a flow passage area may be reduced, resulting in insufficient discharging, and particularly, the bubbling can not be appropriately effected if the holes 902a are closed.
As described above, the conventional bubbly water outlet has utilized the acceleration of the flow by means of the pressure reducing plates and the suction of the external air owing to the pressure reduction in the internal flow passage caused by the acceleration, so that problems such as the pressure loss and closure of the passages can not be avoided.
Further, the bubbly water from the outlet cap 901 arranged at the end of the spout 900 has a size or a diameter which is determined by the cap 901. Therefore, if the cap 901 has a diameter similar to that of the spout 900, the discharged flow has a spread similar to that when the the water is discharged without being bubbled. On the other hand, since the bubbling softens the flow, it can be appropriately used in the shower bath or the like. However, the small discharge area, which is suitable for the spout, is not suitable for the shower bath.
As can be seen from this conventional example, it has been difficult in the conventional structures to bubble the water without limitations with respect to the flow rate, and to maintain a suitable condition for the use without vanishing the bubbles in the water flow. In addition to these problems, there are various problems in appropriately effecting the bubbling of the water.
If several functions such as bubbling the water, straightening the flow and discharging an ordinary flow are incorporated in one faucet, it unavoidably is larger. For example, since it is necessary to arrange passages and holes for introducing the external air into a bubble forming mechanism part, additional passage for the ordinary flow must be disposed at a position avoiding these air passages. Due to such limitations with respect to the design, the structures in which the bubbly flow and a concentrated flow can be selectively used is independently provided with the air passages for the bubbling and the passages for the concentrated flow, resulting in a large size of the outlet opening. Therefore, the device is too large for use as hand sprays in kitchens or the like, which causes problems in handling thereof and also causes various disadvantages in other applications.